Quantitative Analysis Of Hepatitis Research Articles

HEPATITIS B VACCINATION STATUS AMONG A TARGET GROUP BORN IN 1992-2000: A STUDY FROM BULGARIA

The purpose of this study is to determine the prevalence of stress among students of various health Hepatitis B virus (HBV) infection is a significant cause of morbidity and mortality and a leading cause of chronic liver disease. Vaccination has a key role in hepatitis B prevention. Compulsory immunization for all healthy newborns was introduced in Bulgaria in 1992 as part of the WHO global strategy. Purpose: The aim of this study was to determine the extent of post-vaccination seroprotection among persons born in 1992 – 2000 who received recombinant hepatitis B vaccine. Material/methods: A total of 923 serum samples of a target group of vaccinated individuals (412 males and 511 females) at a mean age of 23.0±2.7 years were tested over a two-year period (2018-2019). The quantitative analysis of hepatitis B surface antibodies (anti-HBs) levels was performed by CLIA using a LIAISON® anti-HBs II quantitative diagnostic kit (Dia Sorin, Italy). Results: All 923 individuals included in the study were hepatitis B surface antigen (HBsAg) negative. Protective anti-HBs titers ranging from 11 to >1000 mIU/mL were found in 45.3% of them. The sex distribution of the tested subjects varied significantly between years (p=0.023). The difference in protective anti-HBs levels between the two sexes was non-significant (p>0.05). There was a weak negative correlation between year of birth and anti-HBs titer (Pearson's r=0.351, p<0.001). Conclusions: The results of this large study conducted among subjects immunized against hepatitis B in childhood showed varying levels of post-vaccination seroprotection. On average, 23 years after universal immunization, 54.7% of the study cohort had no protective levels of anti-HBs (negative or equivocal result).

Characterization and prediction of viral loads of Hepatitis B serum samples by using surface-enhanced Raman spectroscopy (SERS)

BackgroundRaman spectroscopy is a promising technique to analyze the body fluids for the purpose of non-invasive disease diagnosis. ObjectivesTo develop a surface-enhanced Raman spectroscopy (SERS) based method for qualitative and quantitative analysis of hepatitis B viral (HBV) infection from blood serum samples. MethodsClinically diagnosed hepatitis B virus (HBV) infected serum samples of patients of different levels of viral loads have been subjected for SERS analysis in comparison with the healthy ones by using silver nanoparticles (Ag NPs) based SERS substrates. The SERS measurements were performed on blood serum samples of 11 healthy and 32 clinically diagnosed HBV patients of different viral load levels of different exponentials including (101, 102 called as low level), (103, 104 called as medium level) and (105, 108 called as high level). Furthermore, multivariate data analysis techniques, Principal Component Analysis (PCA) and Partial Least Square Regression (PLSR) were also performed on SERS spectral data. ResultsThe SERS spectral features due to biochemical changes in HBV positive serum samples associated with the increasing viral loads were established which could be employed for HBV diagnostic purpose. PCA was found helpful for the differentiation between SERS spectral data of serum samples of different levels of HBV infection and healthy individuals. PLSR model developed with standard samples of known viral loads for predicting the viral loads of blind/unknown samples with 99% predicted accuracy. ConclusionSERS can be employed for qualitative and quantitative analysis of HBV infection from blood serum samples.

Quantitative analysis of hepatitis B virus DNA based on raman spectroscopy combined with multivariate statistical methods

Quantitation of hepatitis B virus deoxyribonucleic acid (HBV DNA) is the most accurate method for determining the infection level of hepatitis B. It is a very meaningful means of detecting the different replication states of HBV infection. In this study, HBV DNA was detected and quantified in 499 patients with hepatitis B by confocal Raman spectroscopy combined with multivariate analysis. The effective information related to HBV DNA in spectral data was extracted by different pretreatments according to the vibrational modes of different functional groups. Quantitative analysis of HBV DNA was carried out by using the spectrum in the characteristic range of 807.027–1700.29 cm−1 for spectral peak assignment analysis and using partial least squares to construct a quantitative model. The results show that the regression model is established by combining normalization pretreatment and multivariate analysis methods. The correlation coefficient (Rc) and root mean square error of calibration from the calibration set of the selected feature range are 0.9751 and 0.3881, and the correlation coefficient (Rp) of the verification set and the root mean square error of prediction from the prediction set are 0.9673 and 0.4314. respectively. In clinical medical applications, Raman spectroscopy combined with diversified analysis methods has great research potential for the quantitative detection of HBV DNA in HBV serum.

Quantitative analysis of hepatitis B virion stability upon single-site amino acid mutation based on computational nanotechnology

Computational biology is an interdisciplinary field that applies the techniques of computer science, functional mathematics and statistics to address problems inspired by biology. Numerous studies have shown that structure of proteins contribute towards their functionality in a direct or indirect way. The structure of viral capsid proteins are critical for hosting and shielding the genetic material and are also crucial for viral entry. In this work, molecular energetics of mutated hepatitis B capsid protein dimer was studied for determining the stability of the virus upon single-site amino acid mutation. Results provide structural information regarding the key residues contributing to hepatitis B virion stability and synthesis. This work illustrates the salience of computational nanotechnology and paves the way for future pharmaceutical applications aimed at the destabilisation of the capsid–surface protein interactions.

1063 Quantitative analysis of hepatitis B virus replicative intermediates in the liver: a comparison of pregenomic RNA vs cccDNA comparison of pregenomic RNA vs cccDNA detection

1063 Quantitative analysis of hepatitis B virus replicative intermediates in the liver: a comparison of pregenomic RNA vs cccDNA comparison of pregenomic RNA vs cccDNA detection

Quantitative analysis of hepatitis C virus in peripheral blood and liver: replication detected only in liver.

Prior studies seeking evidence of viral replication in peripheral lymphocytes of hepatitis C virus (HCV)-infected patients have yielded conflicting results. This study sought to quantitatively determine whether a permissive HCV cell interaction could be detected in leukocytes from infected patients. Peripheral leukocytes from chronically infected patients were purified and were tested for HCV RNA. The results show that virus load is highest in B cells. Other subsets of peripheral leukocytes consistently had very low levels of viral RNA or were negative. Negative-strand HCV was found only in hepatocytes. To determine whether HCV replication could be induced by activation, B cells from HCV-infected patients were stimulated in vitro. No HCV replicating in peripheral leukocytes was detected by a highly sensitive assay. If HCV replication occurs in the leukocyte subsets analyzed here, it is at extremely low levels or occurs under alternate physiological conditions.

Quantitative analysis of hepatitis C virus activity in vivo in different groups of untreated patients.

Highly sensitive competitive PCR (cPCR) and competitive reverse transcription PCR (cRT-PCR) methodologies were recently developed and applied for quantifying viral DNA and RNA species (including HCV RNA) present in clinical samples at low concentration. In this study, we used cRT-PCR to compare the viral load of 118 untreated patients with HCV infection and different clinical conditions (80 patients with chronic hepatitis, 18 infected subjects with persistently normal ALT levels and various degrees of liver injury, 10 HCV infected subjects that tested positive for anti-LKM1 antibodies, and 10 patients with HCV infection and cryoglobulinemia). The results indicate that while great individual variability of HCV viremia is detectable even among patients with similar clinical conditions, the mean HCV RNA copy number in samples from patients with different clinical conditions was similar in all groups with the single exception of patients that tested positive for anti-liver-kidney microsomal auto-antibodies type 1 (anti-LKM1); interestingly, lower HCV viremia levels were revealed in these anti-LKM1-positive cases with liver disease of uncertain pathogenesis.

Quantitative analysis of hepatitis C virus RNA in liver biopsies by competitive reverse transcription and polymerase chain reaction

Background/Aims: The determination of HCV-RNA concentration in liver samples is likely to provide interesting insights for the study of disease progression and for evaluation of the efficacy of anti-viral therapy. Methods: a procedure was developed for the precise quantification of HCV-RNA in liver biopsies, based on the competitive reverse transcription-polymerase chain reaction technology. This competitive assay consists of the co-amplification of the target RNA with known amounts of a competitor RNA molecule containing the same sequence as the target plus an insertion in the middle, allowing resolution of the two amplification products by gel electrophoresis. Results: The amounts of HCV-genomic-RNA and β-actin mRNA (the latter being used as an internal standard to overcome the problem of reproducibility of quantitative RNA extraction) were evaluated in liver biopsies of 15 patients affected by hepatitis C virus-positive chronic liver disease at the time of diagnosis. All the patients underwent α-interferon therapy for 6 months and were subsequently followed for at least 1 further year after the end of treatment. Viral RNA concentration (which ranged from 2 to 2.7 × 10 5 HCV-RNA molecules per 10 16 β-actin molecules) directly correlated with the efficacy of treatment, indicating that low levels of viral replication in the liver are associated with a poor response to therapy. Conclusions: This study suggests that the determination of viral load in the liver is an important prognostic tool for the prediction of the efficacy of α-interferon therapy.

Quantitative analysis of hepatitis C virus RNA in serum during interferon alfa therapy

Background: Interferon alfa is effective for controlling disease activity in chronic hepatitis C. However, many responders suffer relapse after cessation of therapy. In the present study, the serum concentration of hepatitis C virus RNA was correlated with a sustained response to interferon therapy. Methods: Fifty-three patients with chronic hepatitis C received a 26-week course of interferon alfa. Hepatitis C virus RNA was quantitated in serum at the beginning and end of treatment using a competitive assay that combined reverse transcription and polymerase chain reaction. Results: In long-term responders, whose alanine aminotransferase levels remained within the normal range during the 24 weeks after therapy, the titer of viral RNA (logarithmic transformed copy numbers per milliliter of serum) before therapy (7.1 ± 1.2) was significantly lower (P < 0.001) than that of short-term responders (8.3 ± 0.5) who had a relapse within the 24 weeks after therapy and nonresponders (8.1 ± 0.4). Multivariate multiple logistic regression showed that the titer of viral RNA before therapy was the strongest independent predictor of a sustained response to interferon-alfa therapy (P = 0.002). Conclusions: The titer of hepatitis C virus RNA is the most important factor influencing the sustained response to interferon treatment.

Quantitative analysis of hepatitis C virus RNA by competitive nested polymerase chain reaction

AbstractA method that allows the quantitation of hepatitis C virus (HCV) RNA is described. The RNA was extracted from serum samples and reverse transcribed. Target cDNA was then co‐amplified by nested polymerase chain reaction with a known amount of competitive template at various concentrations. Since this internal control DNA uses the same primers as those of the target and is distinguishable from the target cDNA after amplification by size, the initial concentration of the target could be estimated by comparing the intensity of the two bands of amplified DNA fragments. That is, if the starting amount of the cDNA and the competitive template are equal, the intensity of the two bands should also be equal. Using this method the amount of HCV RNA in serum samples obtained from 85 patients with chronic hepatitis type C was determined. There was as much as a 100 000‐fold difference in the levels of HCV RNA from patient to patient. A rapid decrease of HCV RNA in a patient treated with interferon is also described.

Quantitative analysis of hepatitis B virus DNA in saliva and semen of chronically infected homosexual men.

Serum, saliva, and semen from fifteen homosexual men who were chronic surface antigen (HBsAg) carriers were quantitatively assayed for hepatitis B virus (HBV) DNA by Southern analysis. HBV DNA (2 pg/ml-42,000 pg/ml) was detected in 11 carriers and correlated with endogenous DNA polymerase activity and e antigen (HBeAg) titer greater than or equal to 1:640. Viral DNA was detected in the saliva, at concentrations indicating a virus titer of 10(5)-10(7)/ml, of eight carriers and in semen from three patients (10(6)-10(7) virions/ml). HBV DNA in saliva and semen had electrophoretic mobilities similar to those in serum HBV DNA, but HBV DNA was present at much lower concentrations (10(-2)-10(-4) that of serum DNA). Results of isopycnic centrifugation suggested that DNA in saliva and semen was virion associated. These data provide an indication of the quantity of virus present in the semen and saliva of HBV carriers and the relative frequency with which shedding of high titers of virus (greater than 10(5) virions/ml) occurs in these secretions.